Motor-integrated pump and fuel supply system therewith

ABSTRACT

A motor-integrated pump ( 10 ) includes a pump portion ( 12 ) and a motor portion ( 14 ) integrally. The pump portion ( 12 ) permits fluid to be drawn thereinto, pressurized and discharged, while the motor portion ( 14 ) drives the pump portion ( 12 ). A pump-portion fluid path ( 47 ), which permits fluid to flow through the pump portion ( 12 ), is independent of a motor-portion fluid path  48,  which permits fluid to flow through the motor portion ( 14 ). A fuel supply system ( 70 ) includes the fuel pump (i.e., the motor-integrated pump) ( 10 ), a suction filter ( 72 ) and a regulator valve ( 74 ) in a modularized manner. Excess fuel discharged from the regulator valve  74  is introduced into the motor-portion fluid path ( 48 ) of the motor portion ( 14 ).

This application claims priority to Japanese patent application serial number 2005-183340, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a motor-integrated pump and a fuel supply system therewith.

2. Description of the Related Art

Certain engines use a fuel supply system provided with a motor-integrated pump as an in-tank fuel pump. The fuel supply system includes a returnless system that permits fuel within a fuel tank to be supplied into an internal combustion engine thereof. The returnless system refers to a system constructed so as to process excess fuel within the fuel tank instead of returning it to the fuel tank via the engine. This system is shown in FIG. 24, and the flow path diagram thereof is shown in FIG. 25.

As shown in FIG. 24, the fuel supply system 370 includes a fuel pump 310, a suction filter 372, a high-pressure filter 373, and a regulator valve 374 in a modularized manner. Also, the fuel supply system 370 is disposed in a reservoir cup 378 disposed in a fuel tank 376, which is shown by dashed line. It should be noted that the high-pressure filter 373 may also be referred to as a “fuel filter,” a “back-end filter,” or a “downstream filter,” while the suction filter 372 may be referred to as a “low-pressure filter,” a “prefilter,” or an “upstream filter.” The regulator valve 374 may be referred to as a “pressure regulator.” Further, the reservoir cup 378 may be referred to as a “subtank.”

The fuel pump 310 is a motor-integrated pump including a pump portion 312 and a motor portion 314. The pump portion 312 permits fuel to be drawn in, pressurized and discharged, while the motor portion 314 drives the pump portion 312. The fuel pump 310 permits fuel in the reservoir cup 378 to be drawn in and pressurized by the pump portion 312. Then, the fuel is discharged into the high-pressure filter 373 through the pump portion 312. It should be noted that the motor portion 314 is constructed with a brush-type DC motor including a commutator (not shown) and brushes (not shown) slidingly contacting with each other. Also, when flowing through the motor portion 314, the fuel, on one hand, cools and lubricates the motor portion 314. On the other hand, foreign particles (not shown) included in the fuel and motor-generated particles (shown as symbol ◯ in FIG. 25) are discharged out of the motor portion 314. Examples of such motor-generated particles include, but are not limited to, brush-wear particles and commutator-wear particles generated by sliding contacts between the commutator (not shown) and the brushes (not shown) of the motor portion 314.

The suction filter 372 is disposed upstream of the fuel pump 310 so as to capture and remove relatively large foreign particles (shown as symbol □ in FIG. 25) included in the fuel drawn into the pump portion 312 of the fuel pump 310. Accordingly, problems occurring in the fuel pump 310 or other devices disposed downstream of the suction filter 372 may be eliminated or at least reduced.

On the other hand, as shown in FIG. 25, the high-pressure filter 373 is disposed downstream of the fuel pump 310 so as to capture and remove relatively small particles (shown as symbol Δ in FIG. 25) and the motor-generated particles (shown as symbol ◯ in FIG. 25) included in the fuel. Accordingly, problems occurring in the regulator valve 374 and the injector 392, as shown in FIG. 24, or other devices disposed downstream of the high-pressure filter 373 may be eliminated or at least reduced.

The regulator valve 374 does not only regulate fuel pressure of the pressurized fuel coming through the high-pressure filter 373, but also discharges excess fuel into the reservoir cup 378. The pressurized fuel (the pressure being regulated by the regulator valve 374) goes through an in-tank fuel supply line 386 disposed within the fuel tank 376 so as to be discharged into an out-tank fuel supply line 388 disposed outside of the fuel tank 376. As shown in FIG. 24, the fuel discharged into the out-tank fuel supply line 388 passes through an engine delivery pipe 390 so as to be injected by an injector 392 into a combustion chamber (not shown) of the engine body 394.

With respect to the said fuel supply system 370, when the fuel pump 310 is driven by the motor portion 314, the fuel in the reservoir cup 378 of the fuel tank 376 is drawn into the suction filter 372 and pressurized. Then, the fuel passes through the pump portion 312 so as to be supplied to the high-pressure filter 373. The fuel having passed through the high-pressure filter 373 is supplied to the out-tank fuel supply line 388 from the in-tank fuel supply line 386. The regulator valve 374 controls the fuel pressure of the pressurized fuel in the in-tank fuel supply line 386 so as to discharge excess of the high-pressure fuel therefrom into the reservoir cup 378. Also, relatively large particles (shown as symbol □ in FIG. 25) of the foreign particles included in the fuel are captured and removed by the suction filter 372. Further, relatively small particles (shown as symbol Δ in FIG. 25) and motor-generated particles (shown as symbol ◯ in FIG. 25) of the foreign particles included in the fuel are captured and removed by the high-pressure filter 373.

U.S. Pat. No. 7,025,561 discloses a motor-integrated pump similar to the fuel pump 310 that permits fuel discharged from a pump portion to be introduced into a motor portion. On the other hand, Japanese Laid-Open Patent Publication No. 11-201085 discloses a motor-integrated pump that does not permit fuel discharged from a pump portion to be introduced into a motor portion. Further, Japanese Laid-Open Patent Publication No. 11-218057 discloses a fuel supply system that permits excess fuel discharged from a regulator valve disposed on the engine side to be returned into a fuel tank. The fuel pump disclosed in Japanese Laid-Open Patent Publication No. 11-218057 also permits fuel discharged from the pump portion to be introduced into the motor portion. Further, according to Japanese Laid-Open Patent Publication No. 11-218057, excess fuel from the regulator valve and cooling fluid are respectively introduced into each chamber formed outer periphery of the fuel pump so as to cool the fuel pump and the fuel including excess fuel.

The fuel pump disclosed in Japanese Laid-Open Patent Publication Nos. 2000-16312 and 11-218057, and the aforementioned fuel pump 310 of the fuel supply system 370 permit fuel pressurized by the pump portion 312 to be introduced into the motor portion 314. This is why motor-generated particles (shown as symbol ◯ in FIG. 25) and relatively small particles (shown as symbol Δ in FIG. 25) should be captured and removed so as to avoid problems occurring in devices disposed downstream thereof (i.e., the regulator valve 374, the injector 392, and the like). Thus, the high-pressure filter 373 is required to be disposed downstream of the fuel pump 310 in the fuel supply system 370. On the other hand, the suction filter 372 is required to be disposed upstream of the fuel pump 310. This is because relatively large foreign particles (shown as symbol □ in FIG. 25) included in the fuel within the fuel tank 376 or the reservoir cup 378 should be captured and removed so as to avoid problems occurring in devices disposed downstream thereof (i.e., the pump portion 312 of the fuel pump 310, and the like).

Accordingly, the conventional fuel supply system 370 requires not only the suction filter 372 but also the high-pressure filter 373. This requirement forces the size and production cost of the fuel supply system 370 to become increased. This drawback is also found in the fuel supply system disclosed in Japanese Laid-Open Patent Publication No. 11-218057. On the other hand, according to the fluid pump of Japanese Laid-Open Publication No. 11-201085, problems caused by motor-generated particles are avoided, because the fuel pressurized by the pump portion is not introduced into the motor portion. However, this construction is not preferable, not only because it is difficult to cool the motor portion efficiently, but also because it is impossible to lubricate sliding contacts in the motor portion and to discharge motor-generated particles having generated in the motor portion.

SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to provide an improved motor-integrated pump and a fuel supply system therewith, in which the motor portion is not only cooled and lubricated but also motor-generated particles are discharged without permitting the fluid discharged from the pump portion to be introduced into the motor portion.

According to one aspect of the present invention, a motor-integrated pump is provided that may include a pump portion for drawing fluid thereinto, pressurizing and then discharging the fluid therefrom, and a motor portion for driving the pump portion. The pump portion includes a pump-portion fluid path permitting the fluid to be introduced into the pump portion, while the motor portion includes a motor-portion fluid path independent of the pump-portion fluid path so as to permit fluid to be introduced into the motor portion. This allows the fluid flowing through the pump-portion fluid path to be discharged without permitting the fluid to be introduced into the motor-portion fluid path. Thus, the fluid introduced into the motor-portion fluid path may cool and lubricate the motor portion, as well as discharging motor-generated particles.

Preferably, the motor portion may include a brush-type DC motor having a commutator and brushes slidingly contacting with each other such that the fluid introduced into the motor-portion fluid path is directed toward the sliding contacts between the commutator and the brushes. According to the motor-integrated pump, the fluid introduced into the fluid path of the motor portion including the brush-type DC motor is directed toward the sliding contacts between the commutator and the brushes. This may eliminate or at least reduce adhesion and biting of foreign particles into the sliding contacts between the commutator and the brushes.

Preferably, the motor portion includes a non-contacting, brushless motor. This configuration makes it possible to cool the motor portion, i.e., a magnetic circuit around a coil or an electrical circuit, with the fluid introduced into the motor-portion fluid path, so as to reduce characteristic changes caused by the exothermic heat. Also, it is possible to eliminate or at least reduce wear on sliding portions such as bearings of the motor portion because the sliding portions are lubricated by the fluid introduced into the motor-portion fluid path.

Preferably, the motor portion includes a rotor such that the fluid introduced into the motor-portion fluid path flows in the direction of the rotor rotation. This may lower rotational resistance of the rotor so as to reduce electric current consumption of the motor portion.

According to another aspect of the present invention, a fuel supply system is provided that may include a fluid pump, a filter, and a motor (also referred to as a motor portion herein). The fluid pump includes an inlet member and an outlet member for bringing fluid in and out. The filter is positioned adjacent the inlet member of the fluid pump. The motor having an inlet member and an outlet member for bringing fluid in and out. The outlet member of the fluid pump is connected to the inlet member of the motor.

Preferably, the fuel supply system further includes a regulator valve, which is positioned between and connected to the fluid pump outlet member and the motor inlet member. More preferably, the fuel supply system includes a jet pump, which is connected to the motor outlet member. Yet more preferably, the fuel supply system further includes a multilayered filter, which includes an outer layer having a coarse filter and an inner layer having a fine filter. Still more preferably, the fuel supply system further includes a plurality of sealing members, at least one of which is positioned adjacent the fluid pump outlet member, the regulator valve, and the motor inlet member.

According to yet another aspect of the present invention, a fuel supply system is provided that may include an in-tank fuel pump for drawing fuel thereinto from a fuel tank, pressurizing and then discharging the fluid therefrom, a suction filter for capturing and removing foreign particles in the fuel drawn into the fuel pump, a regulator valve for controlling fuel pressure of the pressurized fuel by discharging excess fuel from the fuel pump. Preferably, the aforementioned elements are modularized. Also, the fuel pump includes the aforementioned motor-integrated pump such that the excess fuel is discharged and introduced from the regulator valve into the motor-portion fluid path of the motor-integrated pump. This makes it possible to omit a high-pressure filter conventionally required to be disposed downstream of the fuel pump because there are no motor-generated particles included in the fuel introduced into the pump-portion fluid path. This allows the fuel supply system to be more compact and reduces costs.

Since the foreign particles, which are included in the fuel drawn into the fuel pump so as to affect on the contact portions in the pump portion, are captured and removed by the suction filter, it is possible to eliminate or at least reduce problems occurring at sliding contacts in devices disposed downstream of the fuel pump (i.e., the regulator valve, the injector, and the like) such that the life of the fuel pump is increased.

Preferably, the regulator valve is integrated into the fuel pump such that the fuel supply system is made more compact.

Preferably, the fuel pump is provided with a vapor discharge port for permitting vapor included in the fuel introduced into the motor-portion fluid path to be discharged to the outside of the fuel pump.

Preferably, the fuel supply system further includes a jet pump driven by the fuel flow coming through the motor-portion fluid path of the fuel pump so as to transfer fuel. For example, in the case that the fuel supply system includes a reservoir cup disposed within the fuel tank so as to reserve fuel drawn by the fuel pump, it is possible for the jet pump to transfer fuel from the outside of the reservoir cup into the reservoir cup within the fuel tank.

Preferably, the jet pump is integrated into the fuel pump of the fuel supply system. This makes the fuel supply system miniaturized.

Preferably, the fuel supply system further includes a return path for permitting the fuel coming through the motor-portion fluid path of the fuel pump to flow into the suction filter. This mitigates negative pressure occurring within the suction filter not only due to fuel drawing force exerted by the pump portion of the fuel pump but also due to resistance when the fuel passes through the suction filter. Thus, less amount of vapor is formed in the suction filter even when low boiling point components included in the fuel boils in decompression environment under elevated temperature or subatmospheric pressure, so that it is possible to eliminate or at least reduce a drop of the discharge flow amount occurring when the pump portion of the fuel pump draws vapor thereinto.

Preferably, the fuel supply system further includes a vapor separator in the return path. Thus, the vapor separator may separate vapor from the fuel flowing through the return path so as to eliminate or at least reduce the vapor entering into the suction filter.

Preferably, the suction filter further includes multilayered filter media. Thus, foreign particles included in the fuel are efficiently captured and removed by the multilayered filter media in the suction filter.

Preferably, the multilayered filter media are provided with outer layers having coarse filter media, and inner layers having fine filter media. Thus, larger foreign particles are captured and removed by the coarse filter media of the outer layers, while smaller foreign particles are captured and removed by the fine filter media of the inner layers. Accordingly, foreign particles are captured and removed in a phase manner such that the fine filter media of the inner layers are prevented from clogging. As a result, the suction filter becomes longer lasting.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional objects, features and advantages of the present invention will be readily understood after reading the following detailed description together with the claims and the accompanying drawings, in which:

FIG. 1 is a cross sectional view of a motor-integrated pump according to a first embodiment of the present invention;

FIG. 2 is a top view of the motor-integrated pump according to the first embodiment;

FIG. 3 is a bottom view of the motor-integrated pump according to the first embodiment;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is a flow path diagram of the motor-integrated pump according to the first embodiment;

FIG. 6 is a cross sectional view of a motor-integrated pump according to a second embodiment of the present invention;

FIG. 7 is a top view of the motor-integrated pump according to the second embodiment;

FIG. 8 is a bottom view of the motor-integrated pump according to the second embodiment;

FIG. 9 is a cross sectional view of a motor-integrated pump according to a third embodiment of the present invention;

FIG. 10 is a top view of the motor-integrated pump according to the third embodiment;

FIG. 11 is a schematic view, showing a fuel supply system according to a fourth embodiment of the present invention;

FIG. 12 is a flow path diagram of the fuel supply system according to the fourth embodiment;

FIG. 13 is a cross sectional view, showing the periphery of a fuel pump of a fuel supply system according to a fifth embodiment of the present invention;

FIG. 14 is a schematic view, showing a fuel supply system according to a sixth embodiment of the present invention;

FIG. 15 is a schematic view, showing a fuel supply system according to a seventh embodiment of the present invention;

FIG. 16 is a schematic view, showing a fuel supply system according to an eighth embodiment of the present invention;

FIG. 17 is a schematic view, showing a fuel supply system according to a ninth embodiment of the present invention;

FIG. 18 is a schematic view, showing a fuel supply system according to a tenth embodiment of the present invention;

FIG. 19 is a schematic view, showing a fuel supply system according to an eleventh embodiment of the present invention;

FIG. 20 is a schematic view, showing a fuel supply system according to a twelfth embodiment of the present invention;

FIG. 21 is a schematic view, showing a fuel supply system according to a thirteenth embodiment of the present invention;

FIG. 22 is a schematic view, showing a fuel supply system according to a fourteenth embodiment of the present invention;

FIG. 23 is a schematic view, showing a fuel supply system according to a fifteenth embodiment of the present invention;

FIG. 24 is a schematic view, showing a fuel supply system of the conventional art; and

FIG. 25 is a flow path diagram of the fuel supply system of the conventional art.

DETAILED DESCRIPTION OF THE INVENTION

Each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide an improved motor-integrated pump and a fuel supply system therewith. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in conjunction with each other, will now be described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Moreover, various features of the representative examples and the dependent claims may be combined in ways that are not specifically enumerated in order to provide additional useful embodiments of the present teachings. Referring now to the drawings, embodiments of the present invention will be described below.

First Embodiment

A motor-integrated pump of a first embodiment is shown in FIGS. 1 to 5. The motor-integrated pump described as this embodiment is of Westco or impeller type. As shown in FIG. 1, the motor-integrated pump 10 includes a pump portion 12 and a motor portion 14 integrally. The pump portion 12 permits fluid to be drawn thereinto, pressurized and discharged, while the motor portion 14 drives the pump portion 12. The motor-integrated pump 10 is provided with a pump casing 15 as an outer shell thereof. The pump casing 15 includes a substantially cylindrical tubular shell 16, a motor cover 17 closing one end of the tubular shell 16 (i.e., the upper end in FIG. 1), a pump cover 18 closing the other end of the tubular shell 16 (i.e., the lower end in FIG. 1), a pump plate 19 separating the inside of the pump casing 15 into a motor compartment 20, and a pump compartment 21.

Firstly, the motor portion 14 will be described. The motor portion 14 includes a motor such as a brush-type DC motor. The motor portion 14 also includes magnets 23 fixed inside of the tubular shell 16, and a rotor 24 rotatably driven in the tubular shell 16. The rotor 24 includes a substantially cylindrical rotor body 25 having an iron core, a coil, a commutator 26, and the like, as well as a substantially round-bar shaped rotor shaft 27 passing generally through the axis of the rotor body 25 in up and down directions. One end of the rotor shaft 27 (i.e., the upper end in FIG. 1) is rotatably supported by the motor cover 17 via a bearing 28. Similarly, the other end of the rotor shaft 27 (i.e., the lower end in FIG. 1) is rotatably supported by the pump plate 19 via a bearing 29 in such a manner that the rotor shaft 27 passes through the pump plate 19. It should be noted that the commutator 26 of the rotor body 25 faces the motor cover 17 with a predetermined spacing.

As shown in FIG. 4, the motor cover 17 incorporates brushes 30 slidingly contacting with the commutator 26 of the rotor body 25, springs 31 pressing the brushes 30 against the commutator 26, and the like. Although not shown, the motor cover 17 is provided with a connector including a terminal electrically connected with the brushes 30. Further, the terminal of the connector, brushes 30, and the commutator 26 permit the coil (not shown) of the rotor body 25 to be energized such that the rotor 24 is rotatably driven.

As shown in FIGS. 1 and 2, the motor cover 17 is provided with an inflow port 33 and an outflow port 35. As shown in FIG. 1, the inflow port 33 and the outflow port 35 upwardly open, while they downwardly open to communicate with the motor compartment 20. The opening-end of the inflow port 33 facing downwardly in FIG. 1 (i.e. to the motor compartment 20) is opposed to the end face of the commutator 26 of the rotor body 25 (i.e. the upper end face in FIG. 1). Further, as shown in FIGS. 1 and 2, the inflow port 33 and the outflow port 35 are formed substantially symmetrical with each other in relation to the rotor shaft 27 of the rotor 24.

Next, the pump portion 12 will be described. As shown in FIG. 1, there is a substantially disk-shaped impeller 37 rotatably provided within the pump compartment 21. The outer periphery of the impeller 37 is provided with a plurality of vane grooves 38, which are arranged respectively with a predetermined spacing in the circumferential direction on both of the front and back sides of the impeller 37. The vane grooves 38 on one side communicate with those on the other side through communicating holes 39. Also, the center portion of the impeller 37 is provided with a shaft hole 37 a. The shaft hole 37 a mates with the corresponding end of the rotor shaft 27 of the rotor 24 (i.e. the lower end in FIG. 1) so as to receive torque transmitted from the rotor 24.

The wall surface of the pump cover 18, which is opposed to the impeller 37, is provided with a substantially arc-shaped or C-shaped flow channel 41 associated with the vane grooves 38 of the impeller 37. Similarly, the wall surface of the pump plate 18, which is also opposed to the impeller 37, is provided with a substantially arc-shaped or C-shaped flow channel 42 associated with the vane grooves 38 of the impeller 37. The flow channel 42 of the pump plate 19 and the flow channel 41 of the pump cover 18 are configured in symmetrical relation with respect to the impeller 37.

As shown in FIGS. 1 and 3, the pump cover 18 is provided with an inlet port 43 and an outlet port 44. The inlet port 43 opens downwardly in FIG. 1, while communicating with the starting end of the flow channel 41. The outlet port 44 opens downwardly in FIG. 1, while communicating with the terminating end of the flow channel 41. Further, as shown in FIG. 3, the pump cover 18 is provided with a vapor discharge port 45. The vapor discharge port 45 opens downwardly in FIG. 1, while communicating with a certain portion between the starting and terminating ends along the flow channel 41. The vapor discharge port 45 permits vapor, which is included in the fuel under the pumping cycle caused by the rotation of the impeller 37, to be discharged to the outside of the pump compartment 21.

Next, the operation of the motor-integrated pump 10 will be described. When the coil of the rotor 24 of the motor portion 14 (see FIG. 1) is energized, the rotor 24 is rotatably driven. Then, cooperating with the rotation of the rotor 24, the impeller 37 is rotated in a predetermined direction so as to cause pumping action. Accordingly, fluid is drawn from the inlet port of the pump cover 18 into the starting end of the flow channel 41. The fluid receives kinetic energy with the vane grooves 38, which communicate between one side of the impeller 37 and the other side thereof through the communicating holes 39. Thus, the fluid is pressurized, while being sent from the starting end to the terminating end along both of the flow channels 41, 42 of the pump cover 18 and the pump plate 19. Then, the fluid sent to the terminating end of both of the flow channels 41, 42 is discharged to the outside of the pump 10 through the outlet port 44 of the pump cover 18. It should be noted that the flow path, along which the fluid flows in the pump portion 12, is referred to as a “pump-portion fluid path” (designated by reference numeral 47 shown in FIG. 5).

As opposed to the pump-portion fluid path 47, fluid coming from the inflow port 33 of the motor cover 17 is introduced into the motor compartment 20 so as to be discharged to the outside of the pump 10 through the outflow port 35 of the motor cover 17 as shown in FIG. 1. It should also be noted that the flow path, along which the fluid flows in the motor portion 14, is referred to as a “motor-portion fluid path” (designated by reference numeral 48 in FIG. 5). The motor-portion fluid path 48 is totally or almost totally separated from the pump-portion fluid path 47 such that fluid may not flow from the pump compartment 21 into the motor compartment 20.

As shown in FIG. 5, according to the aforementioned motor-integrated pump 10, the pump-portion fluid path 47, which permits fluid to flow through the pump portion 12, is independent of the motor-portion fluid path 48, which permits fluid to flow through the motor portion 14. This allows the fluid flowing through the pump-portion fluid path 47 to be discharged without permitting the fluid to flow through the motor-portion fluid path 48. Thus, the fluid flowing through the motor-portion fluid path 48 may cool and lubricate the motor portion 14, as well as discharging motor-generated particles. It should be noted that to lubricate the motor portion 14 may be defined as to lubricate the sliding contacts in the motor portion 14. Also, to discharge motor-generated particles may be defined as to discharge fluid together with particles generated within the motor portion 14.

Further, as the motor portion 12 includes a brush-type DC motor, the fluid introduced into the motor-portion fluid path 48 is directed toward the sliding contacts between the commutator 26 and the brushes 30. According to the present embodiment, the fluid is introduced into the motor portion 14 through the inflow port 33 so as to be directed toward the brush-contacting end face 26 a of the commutator 26. Thus, it is possible to remove foreign particles (mainly, brush-wear particles and commutator-wear particles) from the brush-contacting end face 26 a of the commutator 26 so as to eliminate or at least reduce adhesion and biting of such foreign particles into the sliding contacts between the commutator 26 and the brushes 30. It should be noted that the “sliding contacts between the commutator and the brushes” may not only include the brush-contacting end face 26 a of the commutator 26, but also include the commutator-contacting end faces of the brushes 30 and the sliding contacts between the commutator 26 and the brushes 30. Preferably, fluid may be directed to flow from the inflow port 33 of the motor portion 14 to the sliding contacts between the commutator 26 and the brushes 30.

The motor portion 14 may include a non-contacting, brushless motor instead of the brush-type DC motor. This configuration makes it possible to cool the motor portion 14 (i.e., the magnetic circuit around the coil) or the electrical circuit with the fluid flowing into the motor-portion fluid path 48, so as to control characteristic changes caused by the exothermic heat. Also, it is possible to eliminate or at least reduce wear on sliding portions such as bearings of the motor portion 14 because the sliding portions are lubricated by the fluid flowing into the motor-portion fluid path 48.

Second Embodiment

Referring to FIGS. 6 to 8, a motor-integrated pump of a second embodiment will be described. Since the second embodiment is a modification of the first embodiment, the elements previously mentioned above will not be described further. This statement is applicable to the other embodiments disclosed herein.

In the motor-integrated pump 10 of the second embodiment, the inlet port 44 and the outlet port 43 of the pump portion 12, and the inflow port 33 and the outflow port 35 of the motor portion 14 are modified from those of the first embodiment. As shown in FIGS. 6 and 8, with respect to the pump portion 12, the pump casing 15 is provided with an inlet port 51 and an outlet port 55. The inlet port 51 opens substantially radially outward and leftward in FIGS. 6 and 8, while branching inwardly so as to communicate with both of the starting ends, which are formed respectively in the flow channel 41 of the pump cover 18 and in the flow channel 42 of the pump plate 19. Similarly, both of the terminating ends, which are formed respectively in the flow channel 41 of the pump cover 18 and in the flow channel 42 of the pump plate 19, communicate with the outlet port 55, which merges and opens outwardly and leftward in FIG. 8. As shown in FIG. 8, the inlet port 51 and the outlet port 55 are formed substantially parallel to each other.

With respect to the motor portion 14, as shown in FIGS. 6 and 7, the inflow port 33 is formed in the motor cover 17 such that the outer end (i.e., the inflow end) of the inflow port 33 is directed radially outward, while the outflow port 35 is formed in the motor cover 17 such that the outer end (i.e., the outflow end) of the outflow port 35 is directed radially outward. Further, the outer ends of the inflow port 33 and the outflow port 35 are opposed to each other in the direction from side to side in FIGS. 6 and 7. According to the aforementioned motor-integrated pump 10 of the second embodiment, the same effects and results are obtained as in the first embodiment.

Third Embodiment

Referring to FIGS. 9 and 10, a motor-integrated pump of a third embodiment will be described. The third embodiment is a modification of the second embodiment. In the motor-integrated pump 10 of the third embodiment, the inflow port 33 and the outflow port 35 of the motor portion 14 are modified from those of the second embodiment.

As shown in FIG. 9, with respect to the motor portion 14, a tubular shell 16 is provided with an inflow port 60 and an outflow port 62. The inflow port 60 is formed opening at the end near the pump plate 19, i.e., the lower end in FIG. 9, of a motor compartment 20. On the other hand, the outflow port 62 is formed opening at the end near a motor cover 17 (i.e., the upper end in FIG. 9) of the motor compartment 20.

As shown in FIG. 10, the inflow port 60 and the outflow port 62 are arranged in line tangentially to the rotational direction of the rotor 24. The inflow port 60 permits fluid to be introduced into the motor compartment 20 from the outside thereof along the rotational direction of the rotor 24 shown by arrow Y in FIG. 10. On the other hand, the outflow port 62 permits fluid in the motor compartment 20 to be discharged to the outside along the rotational direction of the rotor 24 (see arrow Y in FIG. 10). Thus, fluid flows through the motor compartment 20 along the rotational direction of the rotor 24 in the motor portion 14.

According to the aforementioned motor-integrated pump 10 of the third embodiment, the same effects and results are obtained as in the first and second embodiments. Since the fluid flowing through the fluid path 48 in the motor portion 14 (more specifically, in the motor compartment 20) passes by the rotor 24 along the rotational direction thereof (see arrow Y in FIG. 10), rotational resistance of the rotor 24 is reduced so as to lower the electric current consumption of the motor portion 14.

Fourth Embodiment

Referring to FIGS. 11 and 12, a fuel supply system of a fourth embodiment will be described. This embodiment illustrates a returnless-type fuel supply system using the motor-integrated pump 10 of the first embodiment shown in FIG. 1 as an in-tank fuel pump. The fuel pump is designated by the same reference numeral as the motor-integrated pump.

As shown in FIG. 11, the fuel supply system 70 is disposed in a reservoir cup mounted in a fuel tank 76. The fuel supply system 70 is modularized so as to include not only the fuel pump 10 (i.e., the motor-integrated pump 10) of the first embodiment (see FIG. 1), but also a suction filter 72 and a pressure regulator (i.e. a regulator valve) 74. As shown in FIG. 12, the reservoir cup 78, which may be referred to as a subtank, is disposed at the bottom of the fuel tank 76 such that fuel in the fuel tank 76 flows into the reservoir cup 78 to be reserved.

Firstly, referring to FIG. 12, the suction filter 72 will be described. The suction filter 72 of this embodiment is an integrated filter functioning as both of the suction filter 372 and the high-pressure filter 373, which are described as the conventional art in FIGS. 24 and 25. The suction filter 72 is provided with substantially pouch-shaped filter media 80 and a connection port (not shown) for communicating the inside space of the filter media 80 to the outside. The connection port is connected to the inlet port of the pump portion 12 in the fuel pump 10. The filter media 80 captures and removes foreign particles in fuel drawn into the pump portion 12 of the fuel pump 10 from the inside of the reservoir cup 78. It should be noted that the filter media 80 in the suction filter 72 is configured as multilayered (double-layered in this embodiment) so as to include coarse filter media 81 in the outer layer, and fine media 82 in the inner layer shown in FIG. 12. The outer-layer coarse filter media 81 has substantially the same foreign-particle capture and removal function as that of the conventional suction filter 372 shown in FIG. 25. Similarly, the inner-layer fine filter media 82 has substantially the same foreign-particle capture and removal function as that of the conventional high-pressure filter 373 shown in FIG. 25.

As shown in FIG. 11, the outlet port 44 of the fuel pump 10 is connected to an in-tank fuel supply line 86 disposed inside of the fuel tank 76. The in-tank fuel supply line 86 is connected to an out-tank fuel supply line 88 disposed outside of the fuel tank 76. Fuel discharged into the out-tank fuel supply line 88 passes though an engine delivery pipe 90 so as to be injected by an injector 92 into a combustion chamber (not shown) of an engine body 94. Also, as shown in FIG. 11, the in-tank fuel supply line 86 is provided, near the outlet port 44 of the fuel pump 10, with a check valve 96 for blocking back-flow of the fuel.

The regulator valve 74 controls the fuel pressure of the pressurized fuel in the in-tank fuel supply line 86 so as to discharge excess of the high-pressure fuel. The fuel discharge port of the regulator valve 74 is connected to a return line 98, which leads to the inflow port 33 of the motor portion 14 in the fuel pump 10. Then, the outflow port 35 of the motor portion 14 in the fuel pump 10 is connected to a return line 100, the downstream end of which opens into the reservoir cup 78.

Referring to FIGS. 11 and 12, the operation of the fuel supply system 70 will be described. When the fuel pump 10 is driven, fuel in the reservoir cup 78 passes through the filter media 80 in the suction filter 72 so as to be filtered. During the filtration, the coarse filter media 81 captures and removes relatively large foreign particles (shown as symbol □ in FIG. 12) in the fuel. Similarly, the fine filter media 82 captures and removes relatively small foreign particles (shown as symbol A in FIG. 12) in the fuel.

Then, the fuel having passed the filter media 80 in the suction filter 72 is drawn from the inlet port 43 of the fuel pump 10 into the pump-portion fluid path 47 in the pump portion 12, while being pressurized. Thereafter, the fuel is discharged from the outlet port 44 into the in-tank fuel supply line 86. Further, the fuel passes through the in-tank fuel supply line 86 so as to be supplied to the out-tank fuel supply line 88.

The fuel pressure of the pressurized fuel in the in-tank fuel supply line 86 is controlled by the regulator valve 74 to a predetermined pressure. As shown in FIGS. 12 and 13, during this pressure control process, the regulator valve 74 permits excess fuel to flow into the return line 98. Then, the excess fuel is introduced into the motor portion 14 or the motor-portion fluid path 48, which is disposed in the motor compartment 20 as shown in FIG. 1, via the inflow port 33 of the motor portion 14 of the fuel pump 10. After flowing through the motor-portion fluid path 48, the fuel is discharged into the reservoir cup 78 via the return line 100, which extends from the outflow port 35 of the motor portion 14.

According to this embodiment, as shown in FIG. 12, it is possible to provide the fuel supply system 70 including the fuel pump 10, which, on one hand, allows the fluid flowing through the pump-portion fluid path 47 to be discharged without permitting the fluid to flow through the motor-portion fluid path 48; and, on the other hand, allows the fluid flowing through the motor-portion fluid path 48 to cool and lubricate the motor portion and to discharge motor-generated particles. Also, since there are no motor-generated particles included in the fuel flowing through the pump-portion fluid path 47, it is possible to omit a high-pressure filter 373 (see FIG. 25) conventionally required to be disposed downstream of the fuel pump 10. This allows the fuel supply system 70 to be more compact and reduces costs.

Since the foreign particles, which are included in the fuel drawn into the fuel pump 10 so as to affect the sliding portions mounted in the pump portion 12, are captured and removed by the filter media 80 in the suction filter 72, it is possible to eliminate or at least reduce problems occurring at sliding contacts in devices disposed downstream of the fuel pump 10 (i.e., the regulator valve 74, the injector 29, and the like) such that the life of the fuel pump 10 is increased.

Further, the filter media 80 in the suction filter 72 is configured as multilayered in order to at least include the outer-layer coarse filter media 81 and the inner-layer fine media 82 as shown in FIG. 12. Thus, foreign particles included in the fuel are efficiently captured and removed by the multilayered filter media 80 in the suction filter.

Still further, the multilayered filter media 80 is configured such that the coarse filter media 81 are disposed in the outer layers, while the fine filter media 82 are disposed in the inner layers as shown in FIG. 12. Thus, larger foreign particles are captured and removed by the coarse filter media 81 of the outer layers, while smaller foreign particles are captured and removed by the fine filter media 82 of the inner layers. Accordingly, foreign particles are captured and removed in a phase manner such that the inner-layer fine filter media 82 are prevented from clogging. As a result, the suction filter 72 becomes longer lasting. In addition, the multilayered filter media 80 may be configured to include more than two layers. The hierarchical configuration of the multilayered filter media 80 may be accordingly modified. Alternatively, the suction filter 72 may include a single layer media instead of the multilayered filter media 80.

Since the fuel discharged from the regulator valve 74 is used not only for discharging the motor-generated particles but also for lubricating and cooling the motor portion 14 of the fuel pump 10, the performance degradation of the motor portion 14 is prevented or at least reduced. Also, since the motor compartment 20 of the fuel pump 10 serves as a decompression chamber in order to separate vapor from the fuel discharged from the regulator valve 74, noise produced by the motor portion 14 is advantageously lowered.

Fifth Embodiment

Referring to FIG. 13, a fuel supply system of a fifth embodiment will be described. The fifth embodiment is a modification of the fourth embodiment shown in FIG. 11.

As shown in FIG. 13, the fuel supply system of this embodiment is configured such that the outlet port 44 of the fuel pump 10 is inserted and connected to the upstream end of the in-tank fuel supply line 86, for example, by spigot joint using male and female ends. The connection between the outlet port 44 and the in-tank fuel supply line 86 is maintained sealed by a seal member 103 such as an O-ring. On the other hand, the in-tank fuel supply line 86 is provided integrally with a return line 98 as a branching line. The return line 98 is connected to the regulator valve 74 sealingly with a seal member 105 such as an O-ring. Further, the downstream end of the return line 98 is connected to the inflow port 33 of the fuel pump 10 sealingly with a seal member 108.

According to this embodiment, fuel leakage is prevented or at least reduced due to the sealed connections by the sealing members 103 and 105, respectively between the outlet port 44 of the fuel pump 10 and the upstream end of the in-tank fuel supply line 86, and between the return line 98 and the regulator valve 74. Also, fuel leakage between the inflow port 33 of the fuel pump 10 and the downstream end of return line 98 is prevented or at least reduced due to the sealing connection by the sealing member 108.

Sixth Embodiment

Referring to FIG. 14, a fuel supply system of a sixth embodiment will be described. The sixth embodiment is a modification of the fourth embodiment shown in FIG. 11.

As shown in FIG. 14, the differences between the sixth and the fourth embodiments are: 1) that the regulator valve 74 is integrated into the motor cover 17 of the fuel pump 10, and 2) that the check valve 96 is mounted into the outlet port 44 of the fuel pump 10. Therefore, the fuel supply system 70 of this embodiment is made more compact.

Seventh Embodiment

Referring to FIG. 15, a fuel supply system of a seventh embodiment will be described. The seventh embodiment is a modification of the fourth embodiment shown in FIG. 11.

As shown in FIG. 15, the fuel pump 10 of the seventh embodiment is provided with a vapor discharge port 110, which is disposed, for example, on the motor cover 17 so as to communicate with the outside of the motor compartment 20 as shown in FIG. 1. The vapor discharge port 110 is configured to permit vapor, which is included in fuel flowing through the motor-portion fluid path 48 in the motor portion 14, to be discharged to the outside of the pump 10. Also, the suction filter 72 is provided with a vapor separator 112 on the filter media 80. The vapor separator 112 includes a vapor separating housing 113, which is substantially inverted cup-shaped on the filter media 80. The vapor separating housing 113 defines an expansion chamber 114 such that the transverse cross section of the return line 100 is smaller than that of the vapor separating housing 113. It should be noted that the top wall of the vapor separating housing 113 is provided with a vapor discharge port 126, through which vapor may be discharged from the expansion chamber 114 to the outside.

As shown in FIG. 15, the upper wall of the vapor separating housing 113 is connected to the downstream end of the return line 100. On the other hand, the lower end of the expansion chamber 14 opens to face the filter media 80 of the suction filter 72. The facing portion of the filter media 80 is provided with a vapor-separating filter 118. Similar to the previous embodiment, the check valve 96 is mounted into the outlet port 44 of the fuel pump 10.

According to the fuel supply system 70 of this embodiment, the vapor discharge port 110 of the fuel pump 10 permits vapor, which is included in the fuel flowing through the motor-portion fluid path 48 (more specifically, in the motor compartment 20) in the motor portion 14, to be discharged to the outside of the pump 10. Vapor included in fuel is discharged to the outside through both of the vapor discharge ports 110 and 126. The vapor discharge port 110 of the fuel pump 10 serves as main, while the vapor discharge port 126 of the vapor separator 112 serves as auxiliary. If all the vapor is discharged through the vapor discharge port 110 of the fuel pump 10, the vapor discharge port 126 of the vapor separator 112 might be omitted. In this case, the vapor separator 112 might serve merely as a relay portion.

Since the fuel supply system 70 further includes a return path 120 for permitting the fuel coming through the motor-portion fluid path 48 of the fuel pump 10 to flow via the return line 100 into the suction filter 72, it is possible to mitigate negative pressure occurring within the suction filter 72 not only due to fuel drawing force exerted by the pump portion 12 of the fuel pump 10 but also due to resistance when the fuel passes through the suction filter 72. Thus, less amount of vapor is formed in the suction filter 72 even when low boiling point components included in the fuel boils in decompression environment under elevated temperature or subatmospheric pressure environments, so that it is possible to eliminate or at least reduce a drop of the discharge flow amount occurring when the pump portion 12 of the fuel pump 10 draws vapor thereinto.

The return path 120 is provided with the vapor separator 112, which may separate the vapor from the fuel flowing through the return path 120 so as to eliminate or at least reduce the vapor entering into the suction filter 72. It should be noted that the vapor separator 112 may be omitted because it is provided as needed.

Since the fuel flowing the return path 120 is decompressed in the expansion chamber 114 of the vapor separating housing 113 such that the vaporizable components in the fuel are transformed into vapor bubbles, the vapor is readily separated from the pressurized fuel. Further, since the passage of the vapor is restricted by the vapor separating filter 118, which is a part of the filter media 80 of the suction filter 72, it is possible to eliminate or at least reduce the vapor entering into the suction filter 72. Still further, since a part of the filter media 80 of the suction filter 72 is used to form the vapor separating filter 118, it is possible to reduce the number of elements of the fuel supply system 70 so as to permit smaller size and cost than in the case of additionally providing a dedicated vapor separating filter.

Eighth Embodiment

Referring to FIG. 16, a fuel supply system of an eighth embodiment will be described. The eighth embodiment is a modification of the seventh embodiment shown in FIG. 15.

As shown in FIG. 16, according to the eighth embodiment, the motor-integrated pump 10 of the third embodiment shown in FIG. 9 is used as the fuel pump 10. The fuel pump 10 is positioned laterally on the suction filter 72 such that the inlet port 43 of the pump portion 12 is connected to the connection port (not shown) of the suction filter 72. Thus, the outflow port 35 of the motor portion 14 abuts on the filter media 80 of the suction filter 72 in a surface contact manner. The filter media 80 of the suction filter 72 is provided with a vapor-separating filter 122 opposed to the opening end of the outflow port 35 of the motor portion 14. Similar to the seventh embodiment as shown in FIG. 15, the fuel pump 10 includes the vapor discharge port 110 communicating with the outside of the motor compartment 20. It should be noted that the check valve 96 is mounted into the outlet port 44 of the fuel pump 10.

According to the fuel supply system 70 of this embodiment, the same effects and results are obtained as in the seventh embodiment shown in FIG. 15. Advantageously, the overall height of the fuel supply system 70 is configured so as to be lower than that of the previous embodiment, because the fuel pump 10 is positioned laterally.

Ninth Embodiment

Referring to FIG. 17, a fuel supply system of a ninth embodiment will be described. The ninth embodiment is a modification of the seventh embodiment shown in FIG. 15.

As shown in FIG. 17, the vapor separating housing 113 of the vapor separator 112 of this embodiment is provided with the expansion chamber 114, which includes a preparation chamber 124 and a separation chamber 125. The preparation chamber 124 is formed such that the bottom thereof does not communicate with the filter media 80 of the suction filter 72. On the other hand, the separation chamber 125 is formed to open downward so as to face the filter media 80. The separation chamber 125 communicates with the preparation chamber 124 at the upper portion thereof. Further, the top wall of the preparation chamber 124 is connected to the downstream end of the return line 100, while the top wall of the separation chamber 125 is provided with a vapor discharge port 126 so as to discharge vapor to the outside.

According to the fuel supply system 70 of this embodiment, the same effects and results are obtained as in the seventh embodiment shown in FIG. 15. Besides, the fuel flow coming via the return line 100 into the preparation chamber 124 of the expansion chamber 114, when the fuel flow is strong enough, bounces back by colliding with a bottom wall 124 a of the expansion chamber 114. Then, within the expansion chamber 114, the bounced fuel flow is introduced from the preparation chamber 124 into the separation chamber 125 such that vapor included in the fuel flow is discharged through the vapor discharge port 126 of the separation chamber 125. The pressurized fuel, from which almost all the vapor has been separated, is introduced from the separation chamber 125 into the filter media 80 of the suction filter 72 through the vapor separating filter 118. Thus, it is possible to eliminate or at least reduce the vapor entering into the suction filter 72.

Also, the vapor is readily separated from the pressurized fuel, because the pressurized fuel flow entering into the expansion chamber 114 of the vapor separating housing 113 is stirred during the collision with a bottom wall 124 a of the preparation chamber 124 such that the vaporizable components in the fuel are transformed into vapor bubbles.

Tenth Embodiment

Referring to FIG. 18, a fuel supply system of a tenth embodiment will be described. The tenth embodiment is a modification of the seventh embodiment shown in FIG. 15.

As shown in FIG. 18, according to the tenth embodiment, the vapor separating housing 113 of the vapor separator 112 is longitudinally elongated such that the bottom surface of the housing 113 abuts on the filter media 80 of the suction filter 72. The return line 100 extended from the motor portion 14 is connected to the housing 113 in the generally longitudinal middle of the housing 113, while the top portion of the housing 113 is provided a vapor discharge port 128 so as to discharge vapor to the outside.

According to the fuel supply system 70 of this embodiment, the same effects and results are obtained as in the seventh embodiment shown in FIG. 15. Since the vapor separating housing 113 is longitudinally elongated, vapor is separated from the fuel under the force of gravity so that the vapor is discharged through the vapor discharge port 128. Thus, it is possible to eliminate or at least reduce the vapor entering into the suction filter 72.

Eleventh Embodiment

Referring to FIG. 19, a fuel supply system of an eleventh embodiment will be described. The eleventh embodiment is a modification of the fourth embodiment shown in FIG. 11.

As shown in FIG. 19, according to the eleventh embodiment, a jet pump 130, which is driven by the fuel coming through the motor-portion fluid path 48 in the fuel pump 10, is provided so as to transfer fuel into the reservoir cup 78 from the outside thereof within the fuel tank 76. Thus, the downstream end of the return line 100 is connected to the transferring fuel introducing port (not shown) of the jet pump 130. The fuel suction port of the jet pump 130 is connected to a fuel suction line 131, through which fuel existing outside of the reservoir cup 78 and within the fuel tank 76 is drawn into the jet pump 130. On the other hand, the outlet port of the jet pump 130 is connected to a fuel discharge line 132, the downstream end of which opens into the reservoir cup 78.

The jet pump 130 uses a negative pressure effect generated when the pressurized fuel introduced via the return line 100 is discharged into the reservoir cup 78 via the fuel discharge line 132. The effect permits the fuel existing outside of the reservoir cup 78 and within the fuel tank 76 to be drawn into the fuel suction line 131 so as to flow in the jet pump 130 via the fuel suction port (not shown) such that the fuel is fed into the reservoir cup 78 via the fuel discharge line 132. The basic configuration of the jet pump 130 is well known in the art, and will not be described further herein.

Twelfth Embodiment

Referring to FIG. 20, a fuel supply system of a twelfth embodiment will be described. The twelfth embodiment is a modification of the eleventh embodiment shown in FIG. 19.

As shown in FIG. 20, according to the twelfth embodiment, the return line 100 described as the eleventh embodiment is not connected to the jet pump 130 but opens toward the reservoir cup 78. Further, similar to the seventh embodiment shown in FIG. 15, the fuel pump 10 is provided, for example, on the motor cover 17, with the vapor discharge port 110, which communicates the motor compartment 20 with the outside thereof. The vapor discharge port 110 is formed to permit vapor, which is included in fuel flowing through the motor-portion fluid path 48 in the motor portion 14, to be discharged to the outside of the pump 10. The vapor discharge port 110 is connected to the upstream end of a vapor discharge line 134, the downstream end of which is connected to the transferring fuel introducing port (not shown) of the jet pump 130.

The jet pump 130 uses a negative pressure effect generated when the pressurized fuel introduced via the vapor discharge line 134 is discharged into the reservoir cup 78 via the fuel discharge line 132. The effect permits the fuel existing outside of the reservoir cup 78 and within the fuel tank 76 to be drawn from the fuel suction line 131 so as to flow in the jet pump 130 via the fuel suction port (not shown) such that the fuel is fed into the reservoir cup 78 via the fuel discharge line 132. The jet pump 130 is driven by the fuel coming through the motor-portion fluid path 48 in the fuel pump 10 so as to transfer fuel from outside of the reservoir cup 78 into the reservoir cup 78 within the fuel tank 76. According to the fuel supply system 70 of this embodiment, the same effects and results are obtained as in the eleventh embodiment shown in FIG. 19.

Thirteenth Embodiment

Referring to FIG. 21, a fuel supply system of a thirteenth embodiment will be described. The twelfth embodiment is a modification of the eleventh embodiment shown in FIG. 19.

As shown in FIG. 21, according to the thirteenth embodiment, the jet pump 130 of the eleventh embodiment shown in FIG. 19 is integrated into the motor cover 17 of the fuel pump 10. Therefore, the fuel supply system 70 of this embodiment shown in FIG. 21 is made more compact.

Fourteenth Embodiment

Referring to FIG. 22, a fuel supply system of a fourteenth embodiment will be described. The fourteenth embodiment is a modification of the eleventh embodiment shown in FIG. 19.

As shown in FIG. 22, according to the fourteenth embodiment, the return line 100 described as the eleventh embodiment is not connected to the jet pump 130 but opens to the reservoir cup 78. Further, the in-tank fuel supply line 86 of the eleventh embodiment is provided with a branch line 136. The branch line 136 is connected to the transferring fuel introducing port (not shown) of the jet pump 130. Also, the branch line 136 is provided with a check valve 137 for blocking back-flow of the fuel.

The jet pump 130 uses a negative pressure effect generated when the pressurized fuel introduced via the in-tank fuel supply line 86 is discharged into the reservoir cup 78 via the fuel discharge line 132. The effect permits the fuel existing outside of the reservoir cup 78 and within the fuel tank 76 to be drawn into the fuel suction line 131 so as to flow in the jet pump 130 via the fuel suction port (not shown) such that the fuel is fed into the reservoir cup 78 via the fuel discharge line 132. The jet pump 130 is driven by the fuel coming through the pump-portion fluid path 47 in the fuel pump 10 so as to transfer fuel from outside of the reservoir cup 78 into the reservoir cup 78 within the fuel tank 76.

Fifteenth Embodiment

Referring to FIG. 23, a fuel supply system of a fourteenth embodiment will be described. The fifteenth embodiment is a modification of the fourteenth embodiment shown in FIG. 22.

As shown in FIG. 23, according to the fifteenth embodiment, the in-tank fuel supply line 86 is provided with a vapor discharge line 139, instead of the branch line 136 of the fourteenth embodiment shown in FIG. 22. The upstream end of the vapor discharge line 139 is connected to the vapor discharge port 45 (also see FIG. 3) of the pump cover 18 in the fuel pump 10, while the upstream end thereof is connected to the transferring fuel introducing port (not shown) of the jet pump 130.

The jet pump 130 uses a negative pressure effect generated when the pressurized fuel introduced via the vapor discharge line 139 is discharged into the reservoir cup 78 via the fuel discharge line 132. The effect permits the fuel existing outside of the reservoir cup 78 and within the fuel tank 76 to be drawn from the fuel suction line 131 so as to flow in the jet pump 130 via the fuel suction port (not shown) such that the fuel is fed into the reservoir cup 78 via the fuel discharge line 132. The jet pump 130 is driven by the fuel coming through the pump-portion fluid path 47 in the fuel pump 10 so as to transfer fuel from the outside of the reservoir cup 78 into the reservoir cup 78 within the fuel tank 76. According to the fuel supply system 70 of this embodiment, the same effects and results are obtained as in the fourteenth embodiment shown in FIG. 22.

The invention has been described in detail with particular reference to certain representative embodiments thereof, but it will be understood that variations and modifications may be effected within the spirit and scope of the invention.

For example, the motor-integrated pump 10 of the present invention is widely applicable to fluid other than fuel. Also, the present invention is applicable to a multistage motor-integrated pump 10, which includes a plurality of impellers 37. Further, the present invention is applicable to a motor-integrated pump 10, which is of a type other than Westco type, e.g. axial flow type, gear type, and the like. Further, the fuel supply system 70 of the present invention is applicable not only to a returnless system but also to a return system, which permits excess fuel discharged from a regulator valve disposed on the engine side to be returned into a fuel tank. Further, the reservoir cup 78 may be omitted because it is provided as needed. Further, the return line 100 may be omitted because it is provided as needed. Further, the fluid flowing through the motor-portion fluid path 48 may be substituted by fluid other than fuel. Further, at least one of the inlet, outlet, inflow, and outflow ports of the fuel pump 10 may be plurally provided. 

1. A motor-integrated pump, comprising: a pump portion for drawing fluid thereinto, pressurizing and then discharging the fluid therefrom, said pump portion including a pump-portion fluid path permitting the fluid to flow through the pump portion; and a motor portion for driving the pump portion, said motor portion including a motor-portion fluid path independent of the pump-portion fluid path so as to permit fluid to be introduced into the motor portion.
 2. The motor-integrated pump as in claim 1, wherein the motor portion includes a brush-type DC motor having a commutator and brushes slidingly contacting with each other such that the fluid introduced into the motor-portion fluid path is directed toward the sliding contacts between the commutator and the brushes.
 3. The motor-integrated pump as in claim 1, wherein the motor portion further includes a non-contacting, brushless motor.
 4. The motor-integrated pump as in any one of claims 1, wherein the motor portion further includes a rotor such that the fluid introduced into the motor-portion fluid path flows in the direction of the rotor rotation.
 5. A fuel supply system, comprising: a fluid pump, said fluid pump having an inlet member and an outlet member for bringing fluid in and out; a filter positioned adjacent the inlet member of the fluid pump; and a motor, said motor having an inlet member and an outlet member for bringing fluid in and out, wherein the outlet member of the fluid pump is connected to the inlet member of the motor.
 6. The fuel supply system as in claim 5, further comprising a regulator valve, wherein the regulator valve is positioned between and connected to the fluid pump outlet member and the motor inlet member.
 7. The fuel supply system as in claim 6, wherein the regulator valve is positioned on the motor.
 8. The fuel supply system as in claim 5, further comprising a vapor discharge device.
 9. The fuel supply system as in claim 8, wherein the vapor discharge device includes a vapor discharge member positioned on the motor.
 10. The fuel supply system as in claim 8, wherein the vapor discharge device is positioned between the motor outlet member and the filter.
 11. The fuel supply system as in claim 10, wherein the vapor discharge device includes a preparation chamber, a separation chamber, a vapor discharge member and a vapor separating filter, further wherein the vapor separating filter is connected to the filter.
 12. The fuel supply system as in claim 5, further comprising a jet pump.
 13. The fuel supply system as in claim 12, wherein the jet pump is connected to the motor outlet member.
 14. The fuel supply system as in claim 13, wherein the jet pump is positioned on the motor.
 15. The fuel supply system as in claim 12, wherein the motor includes a vapor discharge member, further wherein the jet pump is connected to the vapor discharge member.
 16. The fuel supply system as in claim 12, wherein the jet pump is connected to the fluid pump outlet member.
 17. The fuel supply system as in claim 5, wherein the filter includes a multilayered filter.
 18. The fuel supply system as in claim 17, wherein the multilayered filter includes an outer layer having a coarse filter and an inner layer having a fine filter.
 19. The fuel supply system as in claim 6, further comprising a plurality of sealing members, wherein at least one of the plurality of sealing members is positioned adjacent the fluid pump outlet member, the regulator valve, and the motor inlet member.
 20. A fuel system for providing fuel to an engine, the fuel system comprising: a fuel supply line for supplying fuel to the engine; and a motor-integrated pump means having a pump portion and a motor portion, the motor-integrated pump means being able to direct fuel from the pump portion to the fuel supply line prior to the fuel interacting with the motor portion, and further to direct any excess fuel to the motor portion. 